With all these repeative surveys and experiments I start feeling ashame of my profession. Many times I feel exhausted with all this repetition, too.

The truly creative mind in any field is no more than this: A human creature born abnormally, inhumanely sensitive. To them…a touch is a blow, a sound is a noise, a misfortune is a tragedy, a joy is an ecstasy, a friend is a lover, a lover is a god, and failure is death.” Pearl Buck

It involved injecting something - maybe the chocolate, possibly something else - in the rats' brains. Why not? That would have an obvious relevance, since when I want to eat I don't put things in my mouth I inject them in my brain.

I think someone should put the researchers at the University of Stupid in a cage and inject things in their brains.

Am I going to spend time reading this nonsense? Would that be a better use of one's time than ... Oh, I dunno ... Reading the Critique of Pure Reason in the original German or visiting Machu Pichu.

Whenever I eat chocolate I lose all sense of reason and pig out on anything even slightly chocolatey. That sounds like an addiction.

In all of the universe there is only one person with your exact charateristics. Just like there is only one person with everybody else's characteristics. Effectively, your uniqueness makes you pretty average.

Coffee can be addictive and so can alcohol and a whole host of drugs, but not all people get addicted when they use them. I would assume chocolate may be the same way. It may be a pyscological addition to the buzz from the theobromine or perhaps a physical addiction to some element. Could be it stimulates the pleasure centres of the brain, and some people (rats) get addicted to the buzz. Likely the same area of the brain that is affected by opiates and maryjane.
Addiction does not necessarily mean binging - most people do not binge on coffee but many need a shot first thing in the morning. Same for alcoholics- some are bingers and some are chronic.